The cytosolic iron-sulfur cluster assembly (CIA) pathway is required for replication stress tolerance of cancer cells to Chk1 and ATR inhibitors

Micronutrient Status and Breast Cancer: A Narrative Review

Breast cancer is one of the most common cancers worldwide, at the same time being one of the most prevalent causes of women's death. Many factors such as alcohol, weight fluctuations, or hormonal replacement therapy can potentially contribute to breast cancer development and progression. Another important factor in breast cancer onset includes micronutrient status. In this narrative review, we analyzed 23 micronutrients and their possible influence on breast cancer onset and progression. Further, the aim of this study was to investigate the impact of micronutrient status on the prevention of breast cancer and its possible influence on various therapeutic pathways. We researched meta-analyses, systemic and narrative reviews, retrospective studies, as well as original studies on human and animal models. The results of these studies indicate a possible correlation between the different levels of micronutrients and a decreased risk of breast cancer as well as a better survival rate. However, further studies are necessary to establish adequate doses of supplementation of the chosen micronutrients and the exact mechanisms of micronutrient impact on breast cancer therapy.

The redox requirement and regulation during cell proliferation

The intracellular metabolic network comprises a variety of reduction-oxidation (redox) reactions that occur in a temporally and spatially distinct manner. In order to coordinate these redox processes, mammalian cells utilize a collection of electron-carrying molecules common to many redox reactions, including NAD, NADP, coenzyme Q (CoQ), and glutathione (GSH). This review considers the metabolic basis of redox regulation in the context of cell proliferation by analyzing how cells acquire and utilize electron carriers to maintain directional carbon flux, sustain reductive biosynthesis, and support antioxidant defense. Elucidating the redox requirement during cell proliferation can advance the understanding of human diseases such as cancer, and reveal effective therapeutic opportunities in the clinic.

Targeting ATR in patients with cancer

Pharmacological inhibition of the ataxia telangiectasia and Rad3-related protein serine/threonine kinase (ATR; also known as FRAP-related protein (FRP1)) has emerged as a promising strategy for cancer treatment that exploits synthetic lethal interactions with proteins involved in DNA damage repair, overcomes resistance to other therapies and enhances antitumour immunity. Multiple novel, potent ATR inhibitors are being tested in clinical trials using biomarker-directed approaches and involving patients across a broad range of solid cancer types; some of these inhibitors have now entered phase III trials. Further insight into the complex interactions of ATR with other DNA replication stress response pathway components and with the immune system is necessary in order to optimally harness the potential of ATR inhibitors in the clinic and achieve hypomorphic targeting of the various ATR functions. Furthermore, a deeper understanding of the diverse range of predictive biomarkers of response to ATR inhibitors and of the intraclass differences between these agents could help to refine trial design and patient selection strategies. Key challenges that remain in the clinical development of ATR inhibitors include the optimization of their therapeutic index and the development of rational combinations with these agents. In this Review, we detail the molecular mechanisms regulated by ATR and their clinical relevance, and discuss the challenges that must be addressed to extend the benefit of ATR inhibitors to a broad population of patients with cancer.

Serum autoantibody profiling of oral squamous cell carcinoma patients reveals NUBP2 as a potential diagnostic marker

Introduction

Oral Squamous Cell Carcinoma (OSCC), a common malignancy of the head and neck region, is frequently diagnosed at advanced stages, necessitating the development of efficient diagnostic methods. Profiling autoantibodies generated against tumor-associated antigens have lately demonstrated a promising role in diagnosis, predicting disease course, and response to therapeutics and relapse.

Methods

In the current study, we, for the first time, aimed to identify and evaluate the diagnostic value of autoantibodies in serum samples of patients with OSCC using autoantibody profiling by an immunome protein array. The utility of anti-NUBP2 antibody and tissue positivity in OSCC was further evaluated.

Results and discussion

We identified a total of 53 autoantibodies with significant differential levels between OSCC and control groups, including 25 that were increased in OSCC and 28 that were decreased. These included autoantibodies against Thymidine kinase 1 (TK1), nucleotide-binding protein 2 (NUBP2), and protein pyrroline-5-carboxylate reductase 1 (PYCR1), among others. Immunohistochemical validation indicated positive staining of NUBP2 in a large majority of cases (72%). Further, analysis of OSCC data available in TCGA revealed higher NUBP2 expression correlated with better disease-free patient survival. In conclusion, the differential serum autoantibodies identified in the current study, including those for NUBP2, could be used as potential biomarkers for early diagnosis or as screening biomarkers for OSCC pending investigation in a larger cohort.

Fam96b recruits brain-type creatine kinase to fuel mitotic spindle formation

Mitosis is a complicated and ordered process with high energy demands and metabolite fluxes. Cytosolic creatine kinase (CK), an enzyme involved in ATP homeostasis, has been shown to be essential to chromosome movement during mitotic anaphase in sea urchin. However, it remains elusive for the molecular mechanism underlying the recruitment of cytosolic CK by the mitotic apparatus. In this study, Fam96b/MIP18, a component of the MMXD complex with a function in Fe/S cluster supply, was identified as a brain-type CK (CKB)-binding protein. The binding of Fam96b with CKB was independent of the presence of CKB substrates and did not interfere with CKB activity. Fam96b was prone to oligomerize via the formation of intermolecular disulfide bonds, while the binding of enzymatically active CKB could modulate Fam96b oligomerization. Oligomerized Fam96b recruited CKB and the MMXD complex to associate with the mitotic spindle. Depletion of Fam96b or CKB by siRNA in the HeLa cells led to mitotic defects, which further resulted in retarded cell proliferation, increased cell death and aberrant cell cycle progression. Rescue experiments indicated that both Fam96b oligomerization and CKB activity were essential to the proper formation of mitotic spindle. These findings suggest that Fam96b may act as a scaffold protein to coordinate the supply and homeostasis of ATP and Fe/S clusters during mitosis.